Table 1.

Definitions of common anthropometric measures and their implications for patients with obesity [12]

Anthropometric Measure	Definition	Patient Relevance
Total Body Weight (TBW)	Total body weight of a person	Often used for pediatric dosing. Suboptimal dosing strategy for up to 2/3 of drugs studied in children with obesity [42]
Lean Body Weight (LBW)	Includes weight of muscle, bone, ligaments, tendons, blood volume, internal organs, and some essential fat (i.e., small amounts of fat contained in bone marrow and internal organs)	Sometimes used for dosing in obesity
Fat Free Mass (FFM)	TBW minus all fat in the body (i.e., essential fat and excess fat)	Sometimes used for dosing in obesity
Adjusted Body Weight (AjBW)	TBW with a correction factor to account for metabolically active vs. less active mass (i.e., fat)	Often used for estimating nutrition needs. Also used for dosing aminoglycosides
Ideal Body Weight (IBW)	A theoretical body weight that lies within the “normal” range; does not account for actual patient body composition. Using IBW, all patients of the same height and sex, independent of body habitus, would receive the same drug dose	Sometimes used for dosing in obesity, but can result in underdosing
Body Surface Area (BSA)	The surface area of the human body that takes into account both height and weight	Often used for chemotherapeutic agents